1. Field
Embodiments relate to semiconductor devices and, more specifically, to image sensors.
2. Description of the Related Art
Typically, an image sensor is a semiconductor device that converts optical image into an electrical signal. Such image sensor may be a CMOS type or a charge coupled device (CCD) type. A CMOS type image sensor is abbreviated as CMOS image sensor (CIS). A CIS includes a plurality of pixels in a two-dimensional arrangement, where each and every pixel includes a respective photodiode. Photodiodes convert incident light into an electrical signal.